Allanite-(Nd) is a rare member of the epidote group characterized by a dominance of neodymium in the rare-earth element site. It typically occurs as dark, opaque, prismatic crystals in granitic pegmatites and often exhibits metamictization due to internal radioactive decay. Collectors should look for distinct crystalline forms in pegmatitic environments associated with other rare-earth minerals.

Hardness

5.5-6

Mohs

Luster

Submetallic

Streak

Grey

Transparency

Opaque

mineralrareEpidote Group family

Allanite-(Nd)

Hardness: 5.5-6
Luster: Submetallic
Streak: Grey
Transparency: Opaque

Is this allanite-(nd)?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch allanite-(nd) with a known reference. Allanite-(Nd) sits at Mohs 5.5-6 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Allanite-(Nd) leaves a grey streak.
3
Read the luster
Hold the specimen under a strong light. Allanite-(Nd) typically shows a submetallic luster.
4
Match the color range
Compare against the expected color range: black, brown, dark brown.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals, massive, granular.

Often confused with

Allanite-(Nd) vs. its common look-alikes — and how to tell them apart in the field.

mineral

Allanite-(Ce)

Mohs 5.5-6.5

How to tell apart: Streak differs — Allanite-(Nd) leaves grey, Allanite-(Ce) leaves greyish-white.

How to tell apart: Streak differs — Allanite-(Nd) leaves grey, Epidote leaves white; luster reads submetallic on Allanite-(Nd) and vitreous on Epidote.

How to tell apart: Streak differs — Allanite-(Nd) leaves grey, Allanite leaves gray.

Compare →

Often found alongside allanite-(nd)

Minerals reported to co-occur with allanite-(nd). Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: (Nd,Ca,Ce)₂(Al,Fe³⁺,Fe²⁺)₃(SiO₄)(Si₂O₇)O(OH)
Mohs hardness: 5.5-6
Density: 3.5-4.2 g/cm³
Colors: Black Brown Dark Brown
Streak: Grey
Luster: Submetallic
Transparency: Opaque
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals, Massive, Granular
Cleavage: Poor
Rarity: Rare
Uses: Collector
Host rock: Granite Pegmatites, Syenites, Metamorphic Skarns
Typical price: $20-150 per specimen depending on crystal size and quality

Where rockhounds find allanite-(nd)

Classic worldwide localities

Kola Peninsula, Russia
Madagascar
Norway
Sweden
United States

Field-hunting tip

Look in granite pegmatites, syenites, metamorphic skarns country — that is the host setting where allanite-(nd) typically forms. If you start seeing quartz, feldspar, biotite in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify allanite-(nd)?+

Mohs hardness is 5.5-6. It typically shows a submetallic luster. The streak is grey. Common colors include black, brown, dark brown.

Where is allanite-(nd) found?+

Notable localities include Kola Peninsula, Russia; Madagascar; Norway; Sweden; United States.

How much is allanite-(nd) worth?+

Typical asking prices fall in the range of $20-150 per specimen depending on crystal size and quality. Quality, size, and provenance can move individual specimens well outside that range.

Is allanite-(nd) safe to handle?+

This mineral is radioactive. This mineral contains thorium and sometimes uranium, making it mildly radioactive. Handle with care, avoid creating dust, and wash hands thoroughly after handling; store away from other sensitive mineral specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like allanite-(nd)?+

Allanite-(Nd) is most often confused with Allanite-(Ce), Epidote, Allanite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with allanite-(nd)?+

Allanite-(Nd) commonly co-occurs with Quartz, Feldspar, Biotite, Zircon, Titanite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does allanite-(nd) form in?+

Allanite-(Nd) typically forms in granite pegmatites, syenites, metamorphic skarns. Working float back to the host body is the standard way to chase a fresh occurrence.

What is allanite-(nd) used for?+

Allanite-(Nd) is used in collector.

Find allanite-(nd) on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.